You've tried all of the classic tactics for cockroach elimination — cleaning, sealing your windows, eliminating water sources — and yet, these creepy, crawly insects are still all over the place. This situation can be incredibly frustrating, but your next step really should be to call a professional exterminator. They'll dig deeper and likely recommend one of the following more effective options for cockroach extermination.
Boric Acid Pesticides
Boric acid pesticides are becoming a common option for cockroach extermination largely because the boric acid used is a safer choice than many other chemical insecticides, but is still effective. It also has an effect that goes beyond the cockroaches that actually consume it directly. As gross as it may sound, roaches eat the bodies of their dead comrades. So if a cockroach eats the boric acid and dies, and then another roach eats its body, that second roach will also be exposed to boric acid and die.
Your pest control expert may place cups or containers of boric acid-based substances in places the cockroaches tend to congregate, such as in the backs of cabinets. While you won't want to eat or breathe in the substance, you don't have to worry if you accidentally touch a little of it.
Another option is to have your home tented and fogged with insecticide vapors. This extermination tactic works a lot faster than boric acid. You don't have to wait for the roaches to find it and die off as adults. The fog will find its way into every nook and cranny of your home, killing all life stages of cockroaches within hours, at most.
The downfall of fogging is that you do have to leave your home, usually for a couple of days, to avoid exposure to the pesticides. Fogging can also be quite expensive.
The final common option is to have bait stations put down. Basically, these stations contain a substance that cockroaches find tasty, but that does kill them within a day or two. A roach will find the bait, and then take some back to its nest and share it with others. Bait stations can be very effective and quite affordable, but they are not a safe option if you have children or pets who might touch or eat the bait.
Talk to local pest control services about these three options. They can tell you which one best suits your needs.